Standoff tool



Nov. 26, 1963 D. J. MOORE ETAL STANDOFF TOOL Filed Feb. 6, 1961 FIGZ.

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I Hi 4 0 3 I 4 I P WALTER W. SKIFSTROM DONOVAN J. MOORE ATTORNEY.

FIG.6.

United States Patent M 3,111,750 STANDOFF TOQL Donovan J. Moore, LosAngeles, and Walter W. Skifstrom, Gardens, Calif assignors to SpaceTechnology Laboratories, Inc., Los Angeles, Calif, a corporation ofDelaware Filed Feb. 6, 1961, Ser. No. 87,151 3 Claims. (Cl. 29235) Thisinvention relates to a standoff tool for inserting friction fitterminals into previously assembled bulkhead partitions of electronicchassis.

Terminals of the so-called friction fit variety have become widely usedin the electronic packaging industry due to their high electricalperformance and their high reliability in maintaining positionalalignment. The friction fit terminal consists of a circular insulatingbushing member, usually constructed of a polyester such as Teflon, andan electrical conducting member centrally located within said bushingmember. The electrical conductor may be of any shape or size dependingon the needs of the particular installation. The terminal is insertedinto an opening having a diameter that is less than the diameter of theinsulating member, thereby requiring a slight flowing and deformation ofthe bushing member. This type of fit is known as an interference fit.One of the more successful of these friction fit terminals is the Press-Fit terminal manufactured by the Sealectro Corporation, which uses aTeflon bushing. The Tefion bushing of the Press-Fit terminal is formedwith a shoulder at one end to provide a bearing surface for limiting thetravel of the terminal.

The terminals are normally installed in the chassis by means of machinetools usually arranged to hold the conductive portion of the terminaland provide an axial force until the Teflon bushing has been insertedand held in place by the shoulder portion. This type of installation ispreferred, since it is desired that a force coaxial with the terminal bemaintained until the bushing is properly sealed.

In the design and construction of highly sophisticated electronicequipment, it is usually required that each stage and subchassis beelectromagnetically sealed from each other. This has necessitated theconstruction of chassis members that are compartmentalized by means of aplurality iof bulkhead members. In order to provide the high degree ofshielding necessary, these bulkhead members are usually soldered to thebasic member and then completely plated with an electrical conductorhaving a high conductivity such as gold or other similar material. Theplacement of a terminal in a bulkhead member of the type just describedbecomes almost an impossibility due to the defined interference fit andthe inability of an operator to maintain a force coaxial with theterminal.

This invention is concerned with a hand tool that holds the terminal andsupplies the necessary force and in the proper direction so as toproperly and easily insert the oversized Teflon bushing into the matinghole. The tool is adapted to be hand operated and is arranged to holddifferent sized terminals for insertion into bulkhead members that arepresently inaccessible by present day techniques.

Further objects and advantages of the present invention will bedescribed as the description progresses, reference now being made to theaccompanying drawings wherein:

FIG. 1 illustrates a preferred embodiment of the tool in the process ofinserting a terminal member;

FIG. 2 is a partial view of the tool illustrating a second embodimentfor holding a plurality of terminal members;

FIG. 3 is a section taken along line 3-3 of FIG. 1

3 ,lll,750 Patented Nov. 26, 1963 illustrating the holding member andanvil member of the tool in greater detail;

FIG. 4 is a partial section taken along line 6-3 of FIG. 1 illustratinga first step in inserting a terminal member;

FIG. 5 is a partial section taken along line 3-3 of FIG. 1 illustratinga second step in inserting a terminal member;

FIG. 6 is an exploded view of the split chuck member forming part of thetool illustrated in FIG. 1; and

FIG. 7 is a pictorial view of a chassis member having a plurality ofbulkhead members and a number of terminal members inserted therein, inaccordance with the present invention.

Referring now to FIG. 1, there is shown a chassis member 10 having aplurality of bulkhead members 11 and 12 each arranged with a pluralityof holes 13 adapted to receive a terminal 14. The terminal 14 is of thetype commonly known as a feedthrough terminal and consists of aconductive member 15 and an insulating bushing 16. As the descriptionprogresses it will be realized that other types of terminals, such asstandoifs, feedthrough, and connectors, may be used. The aforementionedterminals differ only in the shape of the conductive member 15. The sizeof the various terminals will usually be determined by their currentcarrying capacity and as such will be reflected in a larger sizedconductive member 15 and a larger sized insulating bushing 16. Therelationship, however, between the diameter of the hole 13 and thediameter of the insulating bushing 16 is always the same in that thediameter of the bushing 16 is approximately 0.003 to 0.005 larger thanthe diameter of the hole, thereby insuring an interference fit. Theterminal 16 is supported by means of an adjustable split chuck l7rotatably supported at one end of a tool 13. Opposing the split chuck'17 is a rotatably mounted anvil 19 having an opening which has adiameter that is at least larger than the largest insulating bushingused. The tool 18 consists of a pair of hand operated lever arms 2i) and21 pivoted together and arranged to cause a relative movement betweenthe split chuck 17 and the anvil 19. The particular embodimentillustrated causes a direct force between the split chuck '17 and theanvil 19 that is coaxial with the terminal 14 held by the split chuck.The split chuck 17 is supported at one end of a support arm 22, whicharm is pivotally connected to lever arm 21 and slidably attached tolever arm Zll. In a similar manner, the anvil 19 is located at one endof a support arm 23 opposite the split chuck 17. The arm '23 ispivotally connected to lever arm '20 and slidably attached to lever arm21. The defined pivotal connections on support arms 22 and 23 define aparallelogram which establishes a parallel motion between arms 22 and23, upon lever arms and 21 being moved.

Referring now to FIG. 2, there is illustrated a six sided split chuck 24having the ability to support at least six different sized terminalmembers 14.

Referring now to FIG. 3, there is shown a section taken along lines 33of FIG. 1 illustrating in more detail the construction of the splitchuck 17 and the anvil 19. The support arm 22 illustrated in FIG. 1 ispreferably constructed of a pair of similar arms 25 and 26. Locatedbetween said arms 25 and 26 is the split chuck 17. The split chuck 17may have any number of faces, such as the four faces illustrated in FIG.1 or the six faces illustrated in FIG. 2. Each face has a differentsized hole drilled radially for accepting the conductive member 15 ofthe terminal 14. Greater adaptability and support of the terminalmembers are achieved by constructing the split chuck 17 from a pair ofmatching face members 27 and 28 which are held intermediate arms 25 and26. The complete assembly includes a friction spring 29 and is heldtogether by means of a suitable rivet 30. In actual practice the splitchuck 17 is rotatable in order to allow selection of the particular facehaving the desired opening for holding a given sized terminal. Thefriction spring 29 provides the necessary force for holding the splitface 27 and 28 members together. The anvil 19 is located Within a pairof similar arms 31 and 32 which comprise member 23 in a similar mannerthat arms 25' and 26 define arm 22. The anvil 19 is required only tocontain an opening 33 having a greater diameter than the diameter of thelargest insulating insert used. The complete anvil assembly is joined toarms 31 and 32 by means of a rivet 35 thereby making the anvil assemblyrotatable and adaptable to the needs of the tool 18.

FIGS. 4 and 5 illustrate the steps necessary to insert the termn-ial 14into the opening 13. One end of the conductive member 15 is insertedinto the split chuck 17 located at one end of the tool 18. This servesto support terminal member 14 in any position as required by thegeometry of the bulkhead member 12. In operation, the anvil 19 ispressed against one side of the bulkhead member 12 and the bushing 16 isplaced against the opening 13 in the bulkhead opening 12. Since .theopening 13 has a smaller diameter than the diameter of the bushing 16,it is necessary that a continuous and direct pressure he applied on thelever members 20 and 21 so to axially drive the split chuck member 17against the anvil member. A shoulder 36 is formed on the bushing 16 andacts as a limiting stop on the insertion of the terminal member 14 intothe bulkhead 12. The deformation of the bushing 16 provides thenecessary elastic force to rigidly set the terminal member in place.Simply reversing the direction on the lever members 20 and 2.1 willcause the chuck member 17 to slip on the conductive member 15 therebyallowing the chuck member to be pulled free of the terminal.

Referring now to FIG. 6, there is shown an exploded view illustratingthe split chuck composed of face members 27' and 28 that are held inmating relationship by means of arms 25 and 26 and friction spring 29.The different sized grooves 37 and 38 for accepting different sizedterminal diameters are more fully illustrated and realized.

Referring now to FIG. 7, there is shown a pictorial representation of atypical compartmentalized chassis formed by the bulkhead members 12.This figure illustrates how ineffectual pliers or other similar toolswould be for inserting terminal members 14 into an interference fitlocated in the bulkhead defined by the bushings 16 and the holes 13. Itwill be appreciated also that with the great need for high densitypackaging and the larger depth chassis used, that the problem ofinserting a terminal in the bottornmost portion of the bulkhead membersis practically impossible without the tool described in the presentinvention.

This completes the embodiment of the invention illustrated herein;however, many modifications and advantages thereof will be apparent topersons skilled in the art without departing from the spirit and scopeof this invention. Accordingly, it is desired that this invention not belimited to the particular details of the embodiment disclosed hereinexcept as defined by the appended claims.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. A tool for inserting a terminal device, having a conductive memberlocated centrally in an insulating bushing into an opening in a bulkheadmember defining an interference lit with said bushing comprising a pairof actuating levers adapted to be hand operated, a chuck assemblyrotatably mounted at one end of one of said levers, said chuck assemblycomprising split portions adapted to receive the terminal portion ofsaid device therebetween and a spring mounted adjacent the splitportions to bias said split portions into gripping engagement with saidterminal portion, said split portions having a substantially polygonalform defining a plurality of faces, each face having a diiferentdiameter aperture extending perpendicular to the face for accepting andholding different sized terminal devices, and an anvil member rotatablymounted at one end of said other lever and adapted to provide areference for applying a force on said conductive member coaxial withsaid bushing, said anvil member having an opening that is larger thanthe diameter of the bushing being inserted, said anvil member and saidchuck assembly being disposed on similar portions of said levers wherebymovement of said levers causes relative movement between said opposinganvil member and said chuck assembly.

2. A tool for inserting a terminal device, having a conductive memberlocated centrally in an insulating bushing, into an opening in abulkhead member defining an interference fit with said bushingcomprising :a chuck assembly movably mounted at one end of a firstsupporting member, said chuck assembly comprising split portions adaptedto receive the terminal portion of said device therebetween and a springmounted adjacent the split poitions to bias said split portions intogripping engagement with said terminal portion, an anvil member movablymounted at one end of a second supporting member and adapted to providea reference for applying a force on said conductive member coaxial withsaid bushing, and a pair of actuating levers pivotally connected to saidfirst and sec ond members for causing relative parallel movement between said members upon movement of said levers, said anvil member andsaid chuck assembly being disposed on a similar but opposing portion ofsaid first and second member respectively.

3. A tool for inserting a terminal device, having a conductive memberlocated centrally in an insulating bushing, into an opening in abulkhead member defining an interference fit with said bushingcomprising a chuck assembly pivotally mounted at one end of a firstsupporting member, said chuck assembly comprising split portions adaptedto receive the terminal portion of said device therebetween and a springmounted adjacent the split portions to bias said split portions intogripping engagement with said terminal portion, said split portionshaving a substantially polygonal form defining a plurality of faces,each fiace having a different diameter aperture extending perpendicular.to the face for accepting and holding different sized terminal devices,and an anvil member pivotally mounted at one end of a second supportingmember and adapted to provide a reference for applying a force on saidconductive member coaxial with said bushing, said anvil member having anopening that is larger than the diameter of the bushing being inserted,and a pair of actuating levers pivotally connected to said first andsecond members for causing relative parallel movement between said firstand second members upon movement of said levers, said anvil member andsaid chuck assembly being disposed on a similar but opposing portion ofsaid first and second member respectively.

References Cited in the file of this patent UNITED STATES PATENTS

1. A TOOL FOR INSERTING A TERMINAL DEVICE, HAVING A CONDUCTIVE MEMBERLOCATED CENTRALLY IN AN INSULATING BUSHING INTO AN OPENING IN A BULKHEADMEMBER DEFINING AN INTERFERENCE FIT WITH SAID BUSHING COMPRISING A PAIROF ACTUATING LEVERS ADAPTED TO BE HAND OPERATED, A CHUCK ASSEMBLYROTATABLY MOUNTED AT ONE END OF ONE OF SAID LEVERS, SAID CHUCK ASSEMBLYCOMPRISING SPLIT PORTIONS ADAPTED TO RECEIVE THE TERMINAL PORTION OFSAID DEVICE THEREBETWEEN AND A SPRING MOUNTED ADJACENT THE SPLITPORTIONS TO BIAS SAID SPLIT PORTIONS INTO GRIPPING ENGAGEMENT WITH SAIDTERMINAL PORTION, SAID SPLIT PORTIONS HAVING A SUBSTANTIALLY POLYGONALFORM DEFINING A PLURALITY OF FACES, EACH FACE HAVING A DIFFERENTDIAMETER APERTURE EXTENDING PERPENDICULAR TO THE FACE FOR ACCEPTING ANDHOLDING DIFFERENT SIZED TERMINAL DEVICES, AND AN ANVIL MEMBER ROTATABLYMOUNTED AT ONE END OF SAID OTHER LEVER AND ADAPTED TO PROVIDE AREFERENCE FOR APPLYING A FORCE ON SAID CONDUCTIVE MEMBER COAXIAL WITHSAID BUSHING, SAID ANVIL MEMBER HAVING AN OPENING THAT IS LARGER THANTHE DIAMETER OF THE BUSHING BEING INSERTED, SAID ANVIL MEMBER AND SAIDCHUCK ASSEMBLY BEING DISPOSED ON SIMILAR PORTIONS OF SAID LEVERS WHEREBYMOVMENT OF SAID LEVERS CAUSES RELATIVE MOVEMENT BETWEEN SAID OPPOSINGANVIL MEMBER AND SAID CHUCK ASSEMBLY.